Method and means for collecting flexible sheets



ANTON Re STOBB ATTORNEY April 19, 1960 A. R. sToBB 2,933,313

METHOD AND MEANS FOR COLLECTING FLEXIBLE SHEETS Filed Jan. 27, 1958 4 Sheets-Sheet 2 JQ S Q@ N Ym N .E s u* N Q @a en Q /NVE/VTOQ:

I XLS Amom R. so Bk jj l\ 5n- C&\\\ Ar Tom/5y April 19, 1960 A. R. sToBB 2,933,313

METHOD AND MEANS FOR COLLECTING FLEXIBLE SHEETS Filed Jan. 27, 1958 4 Sheets-Sheet 5 FBJ) WE/WOR:

ANTON R. SOBB A T TURA/EV A. R. STOBB April 19, 1960 METHOD AND MEANS FOR COLLECTING FLEXIBLE SHEETS 27, 195B 4 Sheets-Sheet 4 Filed Jan.

/NVEA/TQR.- NTUN I?. SOBB ATTORNEY United States Patent() METHOD AND MEANS FOR COLLECTING FLEXIBLE SHEETS Anton R. Stobb, Racine, Wis.

Application January 27, 1958, Serial No. 711,516

Claims. (Cl. 271-68) This invention relates to a method and a means for collecting flexible sheets, and, more particularly, it relates to the control of the speed of the sheets at different phases of their travel from a source to a receiver or box. Also see my companion Patent No. 2,933,314, application Serial No. 711,515.

Flexible sheets, such as printed signatures of books, magazines, newspapers, pamphlets, etc., can be passed from a source, such as a printing press or a folder, onto a conveyor which deposits the sheets in a receiver or box without interruption of the flow of the sheets. Normally, the sheets issue from the source at a continuous and high rate of speed since the press and/ or the folder are operated at the high rate of speed. It has long been the concern of the graphic arts industry to stack the printed sheets into bundles so they can be tied for shipping. Frequently, the work of two or three laborers is required to scoop the sheets olf the conveyor and stack and pack them and then tie them. Even then, where the sheets are folded, there is no easy way to adjust or control the folds, even though the folds might not be exactly as desired because of the problems inherent in sheet folding, including varying sheet thicknesses, the number of sheets folded together, the number of folds, control of the light weight sheets affected by atmospheric pressure, and like factors affecting the folds. It should be understood that the sheets are normally fed from the source and onto a conveyor which operates at a speed related to the speed of the feed so that the sheets are echeloned or overlapped on the conveyor.

It is an object of this invention to provide a method and means of collecting exible sheets, especially those which are folded into signature form, wherein the speed of the sheets is controlled at different phases of their.

travel from a source to a receiver or box. lIn accomplishing this object, accommodation can be made for different signatures of different thicknesses so that their speed in the receiver, for instance, can be regulated according to signature thicknesses.

Another object of this invention is to provide a method and means of collecting -exible sheets wherein the speeds of the opposit faces of the sheets are controlled. In accomplishing this object, the folds in the sheets can be either maintained in their original folded condition, if they are acceptable, or their folds can be altered by increasing the speed of one face of the sheets as related to the other face of the sheets. Also, better control of the sheets and their folds can be maintained when the path of the sheets is angled.

Other objects and advantages will become apparent upon reading the following description in light of the accompanying drawings, wherein:

Fig. l is a side elevational View of a sheet collector showing a preferred embodiment of this invention with parts thereof sectioned and with parts broken away.

Fig. 2 is an enlarged sectional view taken on the line 2--2 of Fig. 1.

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Fig. 3 is a sectional view taken on the line 3 3 of Fig. 2.

Fig. 4 is a view similar to Fig. 3 but showing parts thereof in different positions.

Fig. 5 is a sectional view taken on the angled section line 5-5 of Fig. 1.

Fig. 6 is a sectional view taken on the angled section line 6-6 of Fig. 1.

Fig. 7 is a top plan view of the collector shown in Fig. l, but with parts broken away and with the stack removed.

Fig. 8 is an enlarged side elevational view of one form of a folded signature passed through the machine.

Fig. 9 is an enlarged side elevational View of another form of a folded signature passed through the machine.

Similar reference numerals refer to similar parts throughout the views.

Figs. 1 and 7 best show the overall arrangement of the collector which generally includes a frame 10 which partly supports one conveyor 11 and a second conveyor 12 and a third conveyor 13. These conveyors are shown to respectively consist of a plurality of belts 14, 15 and 16 which extend between the limits of each respective conveyor with the belts trained over rollers or pulleys as shown. The movement of the belts is as indicated by the arrows shown adjacent each belt in Fig. l, and this movement of the beltsU or conveyors mentioned transports flexible sheets 17 between the conveyors 11 and 12 from the horizontal position at the left of the view to a vertical position in the center of the view, at which point the conveyor 13 engages the signatures 17 which are shown to form a stack 18, and the conveyor 13 moves the stack of signatures to the right, as viewed in Fig. 1. It should also be understood that the signatures or sheets 17 are laid upon the lower conveyor 11 as the signatures pass from a sheet folding device (not shown) which processes the sheets at a uniform rate and delivers them onto the conveyor 11 at said uniform rate so that the signatures 17 are overlapped and echeloned, as shown in their position on the conveyor 11. In this arrangement, the signatures 17 form a stream with the leading edge of each signature in contact with the conveyor 12, and it should also be noticed that the stack 18 is formed to the side of the stream opposite to the side Where the signature leading edge is located. In this arrangement, the signatures are automatically deposited onto the conveyor 11 and transported between the conveyors 11 and 12 to the conveyor 13 with the signatures being stripped from their stream position and off the conveyor 12 by means of a stop 19.

The important feature of this invention resides in the control of the speed of the conveyors 11, 12 and 13 in that the speeds of these three conveyors can be varied with respect to each other so that one speed of conveyor 11, for instance, does not result in only one speed for each of the conveyors 12 or 13. different speed, and in achieving this goal, the speed of conveyor 13 can be regulated and set according to the thickness of the signatures 17 so that when the latter are deposited in the stack 1S, the conveyor 13 will move the stack at a rate of speed corresponding to the rate of increase in the stack which, in turn, is, of course, dependent upon the thickness of the signatures coming into the stack 18. Of course, it is the intent and desire that the stack 18 be tightly packed so that the signatures in the stack are ready for binding when the stack is of a certain length or when there is a certain number of signatures in the stack. Also, to vary the speed of the conveyor 11 with respect to the conveyor -1'2 will actually control and affect the fold in the signatures 17 in that, for instance, if the signatures are folded such that the actual fold or line of crease `is toward the top of the In providing for these inthe case ofl a perfect'fold, thenian increase inthe speed of the conveyor 11 will actually cause the lower face or sigepf the signatures to be drawn more rapidly into. the bite or junction between the conveyors 11and '12,*v and thus the lfold in the` signatures would be placed inthe exact desired position. On this latter point, Fig. 8 shows a signature V17 with its leading end of travel bejngthe open end and its trailing end` of travel being the end having the fold or crease line 21, and it is assumed that the' line `of fold is above the top of the horizontal center plane ofthe signature, as mentioned in the foregoing. It should thus1be understood that if the lower face 22 of the signatureV is moved into the bite between the conveyors 11k and12 at a speed faster than the movement of the upper face 23'of the signature, then the lower face 22 will be advanced slightly with respect to the face 23, andrsuch advance will cause the crease line 21 to be lowered to the'horizontal center plane of the signature, as desired. Ofacourse, when'the signatures 17 are overlapped and echeloned, as desired, the whole lower face 22 andithe full upper face 23Y of each signature is not in contact Vwith the respective conveyorsv 11 and 12 but'the latter con; ve'yorsVv do contact-'a'portion 4of the faces, and the speeds ofthe signature faces `can be lgoverned as described to control the location of the fold orv crease line 21.

Fig. .9 shows another 'form o f the signature 17,'and in this ,instance two folds or crease lines 24 and 26 are formed. Again, it is assumed that the folds are not tight and each line may be above its desired position. In-this instance, if the conveyor 12 is faster than the conveyor 11, ,the front edge of the signature will become aligned and the folds 24 and 26 will fall into place.

vIt should, of course, also beunderstood that when,'for instance, thick signaturesare being fed through the collector to the stack 18, then the speed of the conveyor 1'1 should be increased' since the conveyor travels to the outside vof the curved path ofthe stream of signatures, and naturally the outside path is longer than'the inside pathl taken by lthe Vconveyor 12, and, accordingly, the con' veyor 11 should move faster. j The preferred mechanism for accomplishing the function 'and desired result mentioned will now bedescribed. It will be understood that the conveyor 11 is trained about a roller or pulley 27, and passes aV roller 28, Va shaft 29, and pulleys 30 rotatable on a shaft 31, from where vthe conveyor 11 returns to the roller 27 after it passes a rotatably mounted belt guide 32, and is trained about the roller 28, and the conveyor, of course, continues back to the roller or pulley 27 such that the conveyor isV end'- less and trained about the rollers, pulleys, and shafts de.- scribed and shown.

ViAlso, the conveyor 12 is shown trained about pulleys 33 rotatably mounted on a shaft 34 which is supported Ona rody 35 with the latter being adjustably mountedlon the side panels of the frame by virtue of the attachment toY two trunnions 36 which can be adjustably rotated and secured in position on the frame 16) in any well-known manner. Thus, the extended end of the rod'35 carrying the pulleys 33, as shown in Figs. l and 7, provides for selective positioning of the shaft 34V and, therefore, the pulleys 33 can be positioned as desired` The conveyor 12 continues around a roller 37, which is, of course, rotatably mounted in the frame 10 on the shaft 38, and the conveyor is then directed upwardly pasti rotatably mounted belt tighteners 39V and 41, and theV conveyor continues thereabove to another series of pulleys 42 which are mounted for rotation on their shafts 43. Thus, the pulleys 42 can be adjustably positioned as their mounting rod 44 is pivotally attachedv to the frame by the shaft 46, and in this manner, it will be understood and apparent that a like number of pulleys42` is provided to have the belts aligned with the'pulleys 33, and each of the four pulleys 42, which match with the four pulleys 33, can be independently positioned by pivotal positioning of each rodv 44 about the Vmounting shaft 46 so that the pulleysl42 can be selectively dis-I `posed-"inthelongitudinal piane of 'the stack 18; ""Thus;

the path of the conveyor 12 is traced as outlined and, of course, the belts are endless`and continue around in the path outlined. At this moment, it should also be noticed thatY the stop 19 which strips the signatures from the conveyor 1'2 can, of course, be mounted on the upstanding post 47, and such mounting would preferably be adjustable 'so thatthelstop 19`- could move" downwardly, for instance, from its shown position to'accommodate signatures of a shorter length and, accordingly, the height of the stack 18 would be less than that shown.

The conveyor 13is shown in Fig. 7 to be trained between the series` Iof pulleysy48 mountedon the shaft 31 for rotation therewith, and the conveyor extends to the roller l49 which is mounted on the shaft 50 so that the roller 49 can rotate.

`It will, of course, be noticed that in the echeloned relation of the signatures 17,they are normally spaced one behindthc other a distance greater than the thickness of each signature, and thismeans that the stack 1.8 willgmoveY at a yspeed slower than the edgewise speedofv the incoming 'stream` of signatures at the entrance end of the receiver 5S which supports 'the stack 18. Accordi ingly, Athe speed ofthe conveyor 13 is less than that of the conveyorsll and 12, andVY since'the shaft 29 Vat the entrance of' the stream intothe receiver or box 55"is'" powered' to rotate'with the faster conveyor 11,` knurled or fine-toothed rollers 60, mounted on the shaft 29 for rotation therewith, will engage the bottom or trailing edges of the signatures 17 to are or urge, them along the receiver 37 as shown inVFig. 1.

rollers provide a means for frictionally and positively engaging the "trailing, edges of the signatures andad-A S4 trained overthe pulley, and also' trained over another expandable pulley 456 mounted onand for'rotation `with a sllaftf57. vOne end of `the shaft `57 hasl a gear 58 which meshesv with-'a gear '59,supported` on a shaft 61' which is, of course rotated, through the powerl system mentioned, upon operation of the motor 51. Figi 5 shows the-'shaft `61 toextend to a couplingv '62 having a square socket-for rotating the shaft `61 and for rotating a shaft 63 in the other end of the coupling 62. Shaftf 63 extends into a pulley lh'ousing 454V and has an expand-` Y able pulleyf66 mounted on the shaft for rotation therewith' andi for' driving a V-'belt l67 which also is trained on an expandable pulley y68 mounted on a'shaft `69 for rotation therewith. The output of the shaft `69 is transmitted to a hevelfgear 71 which is in mesh with another bevel gear 72 on the lowerv end of an'upstandingshaft 73swhicl1.l is

non-rotatably supported in the frame 10 in aconventional manner. Fig. lrshows that the upper endr of the shaftv 73 has` a wormV 74 mounted-thereon for engagement with a,worrn wheel 76 mounted on ,the shaft 31 such that the Since thel power train-induces rotation of the shaft 31. beltsy 16 ofthe-conveyor '13 areltrained over the pulleys 48.mountedon the-shaft`31, the-belts 16 are driven by,

the power transmission described. Y Y

From-,the foregoing, it willbe understood that o eration: ofthe electric motor 51 rotates the shaft 63 inthe variable speed pulley`r unit 77 which includes the parts described above. It will also be noticed that both of thevariable speed pulley units 77 `and 78 are adjustable so 'that' Vthe output speeds` ofthe take-off oroutput shafts 61 and'v69canbe varied.' To this end, it will beseenin' Figs'. l'and 6 that an 'axial thrust cup or member' 79 is mounted on the shaft 52 lfor axial movementitheralng =In this manner,V the lower or trailing edges of the signatures are moved away` from the incoming stream of signatures so that the'stre'am' hasrnore freedom and space to enter the receiver andY Y formthe stack. `Of course, the knurling or teethon the without impeding rotation of the pulley 53, and a link 81 is pinned to the member 79, and another link 82 is pivotally mounted by a pin 84 on the housing 83 of the unit 78. A threaded stud 86 extends through the wall of the housing 83 and through a xedly mounted threaded socket 87, and the stud 86 has a square end 88 which is rotatably attached and axially movable in a square socket 89. The latter socket is shown in Fig. 1 to be one part of a universal joint with the other part of the joint being the member 91 which has an extension rod 92 attached thereto. The rod extends to a second universal joint 93, and the upper end of the joint 93 has a shaft 94 attached thereto for rotation with the rod 92, and for supporting a bevel gear 96. Also see Fig. 7. The gear 96 is in mesh with another bevel gear 97 which is non-rotatably attached to a shaft 98 which, in turn, is attached to a hand wheel 99 having a handle 101. Thus, upon rotation of the hand wheel 99, the bevel gears 96 :and 97 are rotated to rotate the rod 92 and the stud `86 which is axially displaced in its threaded socket 87. If the hand wheel 99 where rotated to have the stud y86 move downwardly, as viewed in Fig. 6, that is, out of the housing 83, the pulleys 53 would expand as the belt 54 is pulled radially inward on the pulley by virtue of a compression spring 100 exerting an axial force on the expandable pulley 56 to move the belt 54 radially outward on the pulley S6. The expansion of the pulley 53 would reduce the speed of the belt 54, and the speeds of the shafts 57 and 61 would also be reduced. Accordingly, the shaft 63 of the expanding pulley unit 77 would be reduced in speed so that the expandable pulley shaft 69 and the worm wheel shaft 73 would be reduced in speed to reduce the speed of the conveyor 13. This variable speed pulley unit shown is of a conventional design, and no claim is herein made to the invention of it.

When the speed of the shaft 63 is reduced, then a sprocket 102 mounted to rotate with the shaft 63 is also reduced in speed and, correspondingly, the speed of a sprocket 103 mounted on the shaft 104, on which is located the roller 28, is reduced in speed. A chain 106 drivingly connects the sprockets 102 and 103 in the usual manner. It will thus be seen that adjustment of the variable speed unit 78 also affects the speed of the roller 28.

Referring again to the expandable pulley unit 77, it will be seen that adjusting means similar to that described in connection with the unit 78 are attached to the unit 77 for governing the speeds of the output shaft 69. Thus, the speed of the conveyor 13 can be further governed by adjusting the hand wheel 107 which connects through the universal joint 108, the shaft 109, and the universal joint 111, to another stud 86 for movement of another thrust bearing member 79 shown in Fig. 5 on the shaft 63. By this arrangement, the conveyor 13 is further governed in its speed, and such governing at this point is independent of the adjustment of the variable speed unit 78 which drives the conveyor 11 through the chain and sprocket mentioned.

Figs. 1, and 7 also show that a spur gear 112 is mounted on the shaft 104 for rotation therewith, and the `gear is in mesh with another spur gear 113 which is mounted on the shaft 38 to rotate the latter along with its roller 37. Thus, the conveyors 11 and 12 are geared together through the spur gears mentioned, but the following described parts make possible different speeds between the conveyors 11 and 12. Figs. 2 and 3 particularly, show the roller 28 to be expandable in that the roller is composed of four arcuate sections or segments 114 which are movable radial of the roller shaft 104 to expand and contract and thus govern the linear speed of the belts 14 trained around the roller 28. The roller is shown to be provided with an end plate or hub 116 keyed on each end of the shaft 104 with the hubs 116 being left and right handed to include respective arcuate slots 117 which are cam slots as disposed. A stud 118 is V'extended through each `pair of slots 117, and the stud is secured to the hubs by virtue of the bolt heads and nuts shown. A ange or circular member 119 is mounted on each end of the shaft 104 to be rotatable with respect to the shaft, and a cylinder 121 is attached between the members 119 to form a spool-like assembly, such that the entire assembly can rotate together as one unit. Also, the flange members 119 have radial slots 122 disposed therein for receiving blocks 123. The blocks 123 are shown welded to the segments 114 so that radial movement of the blocks induces radial movement of the segments 114, and such movement of the blocks 123 is induced by rotation of the segments 114 to move the studs 118 in the cam slots 117 while the hubs 116 are held against rotation through the shaft 104 and its gear 103. Such rotation of the segments 114 is possible upon loosening of the nuts on the ends of the studs 118, and

the members 119 will rotate slightly on the shaft 104.

Fig. 4 shows the expanded position of the roller 28 While Fig. 3 shows the contracted position yof the roller, and it will thus be noted in comparing the two figures that the rods or studs 118 are at different positions in the slots 117 between the two views. Also, the views show the shaft 104 to have been rotated.

Thus, when the roller 28 is expanded as shown in Fig. 4 for any given speed of rotation of the shaft 104, the speed of the belts 14 will be increased. In this manner, the relative speed between the conveyors 11 and 12 can be controlled and varied.

While a specific embodiment of this invention has been shown and described, it should be obvious that certain changes could be made therein, and the scope of this invention should, therefore, be limited only by the appended claims.

What is claimed is: r

1. In a method of collecting flexible sheets folded into signatures, the steps comprising disposing said signatures in echeloned and overlapped relation with the folds thereof oriented transverse to the direction of echelon, moving said signatures in their edgewise direction of echelon to form a stream of said signatures, moving the one side on one boundary plane of said signatures in said stream at a speed relative to the other side on the other boundary plane of said signatures for moving said folds with respect to the remainder of said signatures, and interrupting the edgewise movement of said signatures for causing the latter to form a stack angularly disposed to said stream within the extent of the terminal end thereof.

2. In a method of collecting flexible sheets folded into signatures, the steps comprising disposing said signatures in echeloned and overlapped relation with the folds thereof oriented transverse to the direction of echelon,l

moving said signatures in their edgewise direction of echelon to form a stream of said signatures, moving the one side on one boundary plane of said signatures in said stream at a speed relative to the speed of the other side on the other boundary plane of said signatures for moving said folds with respect to the remainder of said signatures, interrupting the edgewise movement of said signatures for causing the latter to form a stack angularly disposed to said stream within the extent of the terminal end thereof, and moving said stream and said stack at speeds independent of each other and with said stack speed regulated according to both the signature thickness and the rate of signatures forming said stack.

3. In a method of collecting flexible sheets folded into signatures, the steps comprising disposing said signatures in echeloned and overlapped relation in a lirst plane with the folds thereof oriented transverse to the direction of echelon, moving said signatures in their edgewise direction of echelon to form a stream of said signatures and angling said stream through a bend and into a second plane, moving the sheets of said signatures in said stream and on the longer radii side of said bend at a speed dif- A ferent from the speed of said sheets of said signatures onA the shorter; radii sident?, said Vhrend l.for moving said folds..

plane, moving the side of said signatures on the longer radii side of said bend at av speed relative to the speed of the other side of said signatures on the shorter radii side of ,said bend, interrupting the edgewise movement of said 'signatures and, aligning the leading edges thereof for causing said signature to form a stack angularly disposed to .saidupright planeA and to said stream and be within the extent ofthe terminal end ofsaid stream, and governing thetspeed4 of said stack separate from the speed of said stream.r .Y t t 5-. A collector for fiexible sheets comprising a iirst conveyor and a secondi conveyor with each including a portion parallel to a portion in the otherconveyor and with said'portions disposed for supporting said sheets therebetweeninj an echeloned and overlapped relation and for moving said sheets in a stream in their edgewise direction with the trailing edges of said sheets in contact with said rstconveyor, said portions being disposed through a bend for directing said stream upwardly, means in separate driving relation to each said conveyor for driving each said conveyor at a different speed relative to the speed of the other said conveyor, and a stripper disposed at the downstream edge of said stream for stacking said signatures.

, 6.. A collector for flexible sheets comprising a iirst conveyory and a second conveyor with each including a portion vparallel to a` portion in the other conveyor and with saidportions disposed Afor supporting said sheets therebetween in an echeloned and overlapped relation and'for moving said sheets in a stream in their edgewise direction and through a bend transverse thereto and with the trailing edges of said sheets being on one side of said stream and in contact with said first conveyor, a third conveyor angularly disposed to said stream at a downstream locationzfrom the terminal end ofA said stream and to said one side thereof, a stripper mounted at said terminal end of saidstream for interrupting edgewise movement. of said signatures and stacking the latter on said third conveyor, and/drive means independent driving relation to each said conveyor for driving each said conveyor at speeds relative to the speed of the other said conveyors.

f7. A collector for flexible sheets of folding signatures, comprising a irst conveyor and a second conveyor with each including a portion parallel to a portion in the other Aconveyorand with said portions disposed partly infa iirst plane and 'supporting said sheetsV between said portions in an echeloned and overlapped relatiojnk and `for moving said sheets in a stream in their' edgewise direction with the trailing edges of said sheets in contact with said iirst conveyor, said portioris "ofY said conveyors formed to include a bend for directingsaid stream into a `second plane angled upwardly frnisaid first plane, means in independentdriving relation to each said conveyor for driving each said conveyor atjla speed relative to the speed of the other said conveyorgand a stripper disposed at the downstream edge of saidfstream `for stacking said signatures.

85A collector for flexible sheets comprising a iirst conveyoruanrd a second conveyor with each including a portion parallel ,to a portionin the other conveyor and with said portions disposed for supporting` said sheets` therebetween in an echeloned and overlapped relation and for mQVIS-dshects in a stream in 'their edgewise direction with the-.trailing-'edges zoipsaid .sheets being onfonetside of saidrrstreamand lin contact. with. said rst conveyor? a vthird conveyor angularly disposedto 'said streamat a.,

downstreamlocation .from the terminal end of saidjstrea'm` and to said one side thereof, a stripper mounted at saidA terminal-'end of said stream for interrupting edgewise movement of said signatures and stacking thelatter. on

ing the latterV independent of the speed of said Voutput* shaft.

9. A collector for flexible sheets comprising a first conveyor and a second conveyor with each including a portionparallel to a portion in the other conveyor and with. said portions disposed for supporting said sheets, therebetween'inran echeloned and overlapped relation and for;

moving said sheetspin a stream in their edgewise direction` with the trailing edges of said sheets being on onesdeof said stream` andy in contact with said first conveyor,

. a third conveyor angularly disposed to said stream ata downstream location from the terminal end of said stream.

and to ,saidtone side thereof, a stripper mounted at said terminal end oflvsaid streamV forv interrupting edgewise movement of said signatures and stacking the 'latter on said Vthird conveyor, first drive means connected between said iirst conveyor and said second conveyor for t'rans-V mitting drivingk power therebetween and form a-unit therebetween, a prime mover, a first variable speed trans-` mission disposed between said prime mover and said unit, and a second variable Yspeed transmission disposed between said prime mover and said third conveyon,

moving said sheets in a stream in their edgewise direction` with 4the trailing edges of said sheets being on one side of said stream and in contact with said tirst conveyor,

a rotatably mounted shaft included in said first conveyor, a third conveyor angularly disposed to said streamatga downstream location from the terminal end of said stream andto said one side thereof, a stripper mounted at said terminal end of said stream for interruptingedgew'ise unit therebetween, an expandable roller mounted on 'saidshaft of said first conveyor forv varying the speed ofthe..

i' latter, a Vprime mover, a iirst variable speed transmission disposed between said prime 4mover and said unit, anda second variable speed transmission disposed between said,

overlapped relation and for moving said sheets ina stream in their edgewise direction with the trailing edges of said sheets in contact with said iirst belts, a set `of rollers or pulleys rotatably mounted for supporting each set of said belts, a shaft rotatably mounted and included in each l set of saidrollers or pulleys to provide two'shafts, drive means connecting said two shafts together for rotation at a related'speed, an `expandable ro-iler mounted on one` of said vshafts and having said belts of one said set trainedf thereover ioraltering. said speed of the. latter said belts .z upon expansion` or contraction of saidexpandable roller,

and means for aligning said leading edges of said sheets to form a stack.

12. A collector for flexible sheets of folded signatures, comprising a first conveyor and a second conveyor with each including a portion parallel to a portion in the other conveyor and with said portions disposed for supporting said sheets therebetween in an echeloned and overlapped relation and for moving said sheets in a stream in their edgewise direction with the trailing edges of said sheets in contact with said first conveyor, a rotatably mounted first shaft included in said first conveyor, means for removing said sheets from said stream and forming a stack, a third conveyor for `supporting said stack, a prime mover, a rst and a second variable speed pulley unit driven in series by said prime mover, said first variable speed pulley unit including an output shaft in driving relation to said first shaft of said first conveyor, drive means disposed between said first shaft and said second conveyor, an expandable roller mounted on said first shaft for altering the speed of said rst conveyor upon expansion or contraction of said roller, an input shaft and a take-olf shaft included in said second variable speed pulley unit, said output shaft being in direct drive with said input shaft, and transmission means disposed between said take-off shaft and said third conveyor.

13. A collector for flexible sheets of folded signatures, comprising a first conveyor and a second conveyor with each including a portion parallel to a portion in the other conveyor and with said portions disposed for supporting said sheets therebetween in an echeloned and overlapped relation and for moving said sheets in a stream in their edgewise direction with the trailing edges of said sheets in contact with said first conveyor, a rotatably mounted first shaft included in said first conveyor, means for removing said sheets from said stream and forming a stack, a prime mover, a first and a second variable speed unit driven in series by said prime mover, said rst variable speed unit including an output shaft in driving relation to said shaft of said first conveyor, drive means disposed between said first shaft and said second conveyor, an input shaft and atakeoff shaft included in said second variable speed unit, said output shaft being in direct drive With said input shaft.

14. A collector for flexible sheets of folded signatures, comprising a first conveyor and a second conveyor with each including a portion parallel to a portion in the other conveyor and with said portions disposed for supporting said sheets therebetween in an echeloned and overlapped relation and for moving said sheets in a stream in their edgewise direction with the trailing edges of said sheets in contact with said first conveyor, a rotatably mounted first shaft included in said first conveyor, means for removing said sheets from said stream and forming a stack, a third conveyor for supporting said stack, a prime mover, a first and a second variable speed unit driven in series by said prime mover, said first variable speed unit including an output `shaft in driving relation to said first shaft of said rst conveyor, drive means disposed between said first shaft and said second conveyor, an input shaft and' a takeo shaft included in said second Variable speed unit, said output shaft being in direct drive with said input shaft, and transmission means disposed between said take-off shaft and said third conveyor.

15. A collector for flexible sheets folded into signatures, cimprising a pair of conveyors disposed for supporting said sheets therebetween in an imbricated stream relation and for moving said sheets in their edgewise direction and with the folds thereof being transverse to the direction of imbrication and movement, another conveyor angularly disposed to said stream, means adjacent the terminal end of said stream for interrupting edgewise movement of said sheets and stacking the latter on said another conveyor, and a variable speed drive means connected to said pair of conveyors for moving one thereof at a selected speed relative to the speed of the other thereof.

References Cited in the le of this patent UNlTED STATES PATENTS 1,063,338 Duncan June 3, 1913 2,140,112 Novick Dec. 13, 1938 2,233,850 Rapley Mar. 4, 1941 2,392,746 Labombarde Jan. 8, 1946 2,678,716 Apgar May 18, 1954 

